underground 
: 地下的 n. 
underground 
clandestin ☊ 
dưới đất 
It is best if you take the underground / subway (am.). 
Tốt nhất là bạn đi bằng tàu điện ngầm. * 042 like: underground → →
an underground tank ☊ bể chìm ☊ secret organization, secret society, underground group ☊ hội kín ☊ tunnel, underground passage ☊ đường hầm ☊ overhead/underground cables ☊ cable ☊
an underground garage (= for example under an office building) ☊ garage ☊
a secret underground passage ☊ passage ☊
a tube/an underground station ☊ station ☊
underground passages/caves/streams ☊ underground ☊
underground cables ☊ underground ☊
Rescuers found victims trapped several feet underground. ☊ underground ☊
toxic waste buried deep underground ☊ underground ☊
a network of pipelines running underground ☊ underground ☊
clandestin ☊ le flux des immigrés clandestins en Espagne n’a cessé de grossir ☊
métro ☊ toutes les lignes de métro fonctionnaient ☊
sous-sol ☊ il utilisait les parkings en sous-sol ☊
souterrain ☊ ils découvraient un corridor souterrain ☊